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Stanmore HA7 · Bathroom renovation

Bathroom renovation in Stanmore

Listed mansion flats, cottages built for Stanmore Hall, pipes on show

A Stanmore bathroom may sit inside a listed former mansion, in a listed group of cottages built for Stanmore Hall, or in a house in a conservation area whose appraisal comments on pipework. This page covers what Harrow’s records say about those interiors and their pipework, how Harrow handles building control, electrics and drains for a bathroom, and the help it offers when a bathroom has to be adapted.

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Serving Stanmore from our Hampstead studio · NW3 6DN
020 7101 3168

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Bathroom renovation in Stanmore at a glance

For a bathroom here, two things come before any choice of fittings: whether the room is inside a listed building, and whether a pipe or vent will show on the outside. Among the listed buildings the Little Common appraisal describes are Stanmore Hall (grade II*) and Hill House (grade II), both now converted into flats or apartments, and 36–43 Little Common (grade II), a group of cottages. The Stanmore Hill and Little Common appraisals both warn that numerous or badly sited conduits and water goods can spoil a building’s appearance. The drains, fan and electrics then follow the Building Regulations, with Harrow Building Control where approval is needed.

Planning Data: Stanmore Hall, grade II*, list entry 1194606 · Planning Data: Hill House, Stanmore, grade II, list entry 1079647 · Planning Data (Historic England): 36-43 Little Common, grade II, list entry 1358653 · Harrow: Stanmore Hill Conservation Area Appraisal and Management Strategy, December 2013 (PDF) · Harrow: Little Common Conservation Area Appraisal and Management Strategy, December 2013 (PDF) · Harrow: apply for Building Control

For the whole area, including conservation areas, permissions and working hours, read our Stanmore renovation guide.

Approved guide prices

What does a bathroom renovation cost in Stanmore?

A typical bathroom renovation in Stanmore costs £10,000–£30,000 excluding VAT. The final price depends on the scope, the specification and the complexity of the room, and a fixed written price follows the visit and the design.

Scope of workTypical cost
Typical bathroom renovation£10,000–£30,000

The figure excludes VAT. A standalone bathroom gets its own room-specific quotation; try the cost calculator for a first figure.

The buildings

What the records say about Stanmore’s older interiors

The Little Common appraisal records details from inside two listed former mansions that are now homes, and it explains how a listed group of cottages nearby began.

Hill House is listed grade II and now subdivided into flats, and the December 2013 appraisal says its timber sash windows and doors, often original or otherwise historic, remain intact. It also records what repair works inside revealed: original elements, intricate gold embossed carvings in the roof void, and a series of elegant eighteenth-century arches uncovered when dry rot was removed in the entrance. In a building like this, a bathroom is planned only after the room, its floor and its walls have been looked at closely.

Planning Data: Hill House, Stanmore, grade II, list entry 1079647 · Harrow: Little Common Conservation Area Appraisal and Management Strategy, December 2013 (PDF)

Stanmore Hall, listed grade II* and now converted into apartments, was bought in 1888 by William Knox D’Arcy, who employed Brightwen Binyon to extend the building and William Morris to work on the interior. The appraisal records that the interior was very badly damaged by fire in 1979, and it does not say what survives inside. Nearby, 36–43 Little Common has been a grade II list entry since 25 May 1983; the appraisal says the cottages were built about 1863 to house staff and to stable horses for Stanmore Hall.

Planning Data: Stanmore Hall, grade II*, list entry 1194606 · Harrow: Little Common Conservation Area Appraisal and Management Strategy, December 2013 (PDF) · Planning Data (Historic England): 36-43 Little Common, grade II, list entry 1358653

Permissions and local rules

Consent, pipework and approvals for a Stanmore bathroom

Floors, walls and ceilings in a listed building

Does a bathroom refit in a listed building need consent?

That depends on what the work changes. Harrow says consent is needed “for any internal or external changes that affect special interest”, and that it is the council that decides whether consent is needed. In Stanmore Hall, Hill House or 36–43 Little Common, record the room’s floors, walls, ceilings and joinery, and the route of any new pipe or duct, then ask Harrow which of those changes affect special interest before the design is fixed.

Harrow: listed buildings · Planning Data: Stanmore Hall, grade II*, list entry 1194606 · Planning Data: Hill House, Stanmore, grade II, list entry 1079647 · Planning Data (Historic England): 36-43 Little Common, grade II, list entry 1358653

Pipes and outlets on visible walls

How do the appraisals treat pipework on show?

The Stanmore Hill appraisal says the appearance of many attractive buildings that otherwise keep their original features can be spoilt by badly sited aerials, conduits and numerous water goods. Little Common’s appraisal asks that rainwater goods are kept to a minimum, that replacements match existing details such as hopperheads and cross sections, and that they are made of sympathetic materials, ideally cast iron or aluminium. Where a new bathroom needs an outlet or pipe outside, plan its route before the layout is fixed.

Harrow: Stanmore Hill Conservation Area Appraisal and Management Strategy, December 2013 (PDF) · Harrow: Little Common Conservation Area Appraisal and Management Strategy, December 2013 (PDF)

If you own a former Harrow Council flat

What does the council’s alteration application ask?

Harrow’s application for its own leaseholders requires details of the alteration and the room it is in, who will carry out the work, whether planning permission and building regulations approval have been applied for, and when the work will begin if approved. Have those answers ready before fittings are ordered. The process applies only to Harrow Council flats and maisonettes that have been bought, through Right to Buy or from a previous owner, not to privately owned blocks or houses.

Harrow Council: home alterations permission for leaseholders

Electrics and Harrow Building Control

Which parts of the work need notifying?

Electrical work in a home is notifiable when it installs a new circuit, replaces the consumer unit, or adds to or alters existing circuits in a special location, which includes the space around a bath tap or shower head. Harrow’s charges for applications from 6 April 2026 assume a Part P registered electrician certifies the work under a competent person scheme, such as NICEIC, NAPIT or ELECSA, and add a supplementary charge if not. For full plans and building notices, Harrow withholds the completion certificate until a completion notice is sent.

GOV.UK: Approved Document P, electrical safety in dwellings (2013 edition) · Harrow Building Control: domestic charges, Scheme No.15, Tables B and C, for applications from 6 April 2026 (PDF) · Harrow: apply for Building Control

Working hours, skips, parking and the conservation area maps for the whole area are in our Stanmore guide. Local guidance checked ; requirements depend on the address, the building and the complete proposal.

What the work covers

What a Stanmore bathroom renovation covers

Every waste to the right drain

Each waste is traced to the foul drain before it is reconnected. Harrow’s leaflet says waste from toilets, showers, baths and sinks must not be connected into roof-water downpipes or gullies, because the surface water drain carries discharge to the river untreated. It adds that wrong connections are illegal and that the owner is responsible for putting one right, using a qualified plumber, even if someone else plumbed it in. Sewer leaks, smells or full pipes are reported to Thames Water, Harrow’s sewerage company.

Harrow: leaflet, Is your home polluting Harrow’s rivers? (PDF) · Harrow: flood reporting and advice (undated page, checked 16 October 2026)

Extract air and the fan

Where the bathroom already has an extract fan, Approved Document F says it should be retained or replaced. A room with no ventilation system need not gain one, although more ventilation may be needed if the work would leave the building less compliant than before. Replacing a fan that uses the existing cabling does not need notifying. The scope fixes where the duct leaves the building, keeping the outlet off front walls wherever the structure allows.

GOV.UK: Approved Document F, Volume 1: Dwellings (2021 edition), ventilation

Floor, tanking and the room below

For conversions, Harrow’s 2010 design guide says rooms should be stacked so that bedrooms do not overlap living rooms, kitchens and bathrooms on other floors. Floorboards come up only where the design needs, joists are checked under the bath or shower, and a tanking layer covers the shower area and the floor round the bath, water-tested before any tile is laid.

Harrow: Residential Design Guide Supplementary Planning Document, adopted 15 December 2010 (PDF, file 23276)

How we work

How we run a Stanmore bathroom renovation

  1. Visit

    We see the room, trace where the stack runs, and check which floor it is on and what lies beneath.

  2. Survey

    The drainage falls, the extract route and the floor build-up at the door are measured before a layout is drawn.

  3. Design

    The layout, waterproofing and storage are drawn; where a floor or wall changes, our own architects and structural engineers design it.

  4. Price

    You receive a fixed written price once the design and fittings are agreed.

  5. Installation

    The dates, and any days without a working bathroom, are agreed before work starts.

  6. Handover

    Testing, then care notes for the finishes and fittings. Completed work carries a 12-month defects-rectification period under the JCT contract terms.

Real projects, clearly located

Examples of our bathroom renovation work elsewhere in London

None of these projects is in Stanmore. Each card names where the work was done, so you can judge the finish and the approach before you brief your own.

Your brief

Before you ask for a quotation

  1. Tell us the building’s status

    Say whether the building is on the statutory list, and under which entry, whether it is in the Stanmore Hill or Little Common conservation area, and whether the house appears on one of Harrow’s Article 4 schedules. For a flat, name the freeholder and say whether it was bought from Harrow Council.

  2. Describe the room and its surroundings

    Give the floor the bathroom is on, what lies directly beneath and beside it, where the soil pipe runs if you know, and whether there is an extract fan now. A sketch with measurements helps, as does a note of any fireplace, panelling, cornice or old joinery in the room or next to it.

  3. Say who the room is for

    If the bathroom is being adapted for someone with a disability, say so at the start. A grant from Harrow follows its own steps, with an Occupational Therapist’s assessment and the council’s approved contractors, so decide which route you are taking before any design work begins.

Ready to take the next step? Send the address and a short outline of the work.

Book a free feasibility visit

Questions before you begin

Bathroom renovation in Stanmore: questions

Will you take on a standalone bathroom in Stanmore?

Yes. A standalone bathroom is welcome, whether it is an en-suite in a detached house, the only bathroom of a flat in a converted mansion or a shower room in a cottage. Tell us whether the building is listed, what lies under the room and where the soil pipe runs, because those three answers shape which consents and checks apply before anything is designed.

Can a grant pay for an adapted bathroom?

Harrow’s Disabled Facilities Grant is for private tenants, housing association tenants and homeowners, and can improve access to bathrooms, toilets and wash areas after an Occupational Therapist’s assessment. Eligibility includes intending to live there as the main home for at least five years, and most applications are means tested. All works must be done by Harrow’s approved contractors for the grant to be valid, and a legal charge for up to ten years may be placed on the property if the grant raises its value. Council tenants apply for Major Adaptations instead.

Harrow: home adaptations grants and services (undated page, checked 16 October 2026)

Is there a building control charge for adapting a bathroom?

Harrow’s charges note for applications from 6 April 2026 says no building regulation charge is payable for work to an existing home that provides facilities for a disabled person who lives there, or will live there, as their permanent residence, where the existing facilities could not be used by them, or only with assistance. Ask Harrow to confirm that the exemption applies when the application is made.

Harrow Building Control: domestic charges, Scheme No.15, Tables B and C, for applications from 6 April 2026 (PDF)

Does replacing a bath or basin need building control?

Harrow still links a guidance note written for the 2010 edition of Approved Document G, under the Building Regulations 2000. It explained that replacing a WC with one using no more water, or a washbasin, sink, bidet or fixed bath, needed no building notice or full plans where no underground drainage was touched and no other water or drainage work could prejudice health and safety. That is Harrow’s old explanation, not the current regulations, so confirm with Harrow Building Control first.

Harrow Building Control: guidance note on Approved Document G, 2010 edition (PDF) · Harrow: apply for Building Control

What if work that needed approval goes ahead without it?

Harrow warns that starting building work without the approval it needs might mean expensive alterations or demolishing the work later, going to court and paying a fine, and problems when the property comes to be sold. If you are unsure whether part of a bathroom needs approval, such as a new circuit or a new drain, ask before the old room is stripped out.

Harrow: apply for Building Control · When Building Regulations approval is needed

How much does a bathroom renovation cost in Stanmore?

A typical bathroom renovation in Stanmore costs £10,000–£30,000 excluding VAT. The final price depends on the scope, specification and complexity of the project. We give a fixed written price after the visit and the design.

Book a free feasibility visit

Talk to us about your Stanmore bathroom

Tell us the address and what you want to change in your Stanmore bathroom. We reply within one working day, Monday to Friday, 8am to 6pm.

Or call 020 7101 3168. We serve Stanmore from our studio at Unit 3, Palace Court, 250 Finchley Road, London NW3 6DN.

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